#include <iostream>
#include <string>
#include <cctype>

using namespace std;

void swap(char&	v1, char& v2);
//switches values of v1 and v2
string reverse(const string& s);
//returns string s in reverse order
string remove_punct(const string& s, const string& punct);
//returns string s with punctuation removed
string make_lower(const string& s);
//returns copy of string s with all of the characters lowercase
bool is_pal(const string& s);
//returns true of s is a palindrome, otherwise returns false

int main()
{
    char runagain;
    do{
        string str;
        cout << "Enter a candidate for palindrome testing: ";
        getline(cin, str);
        if(is_pal(str))
            cout << "\"" << str + "\" is a palindrome.";
        else
            cout << "\"" << str + "\" is not a palindrome.";
        cout << endl;
        cout << "Run the program again? (y/n): ";
        cin >> runagain;
        cin.ignore();
        cout << endl;
    } while((runagain == 'y') || (runagain == 'Y'));
    return 0;
}//end main

void swap(char& v1, char& v2)
{
    char temp = v1;
    v1 = v2;
    v2 = temp;
}//end swap

string reverse(const string& s)
{
    int start = 0;
    int end = s.length();
    string temp(s);

    while(start < end)
    {
        end--;
        swap(temp[start], temp[end]);
        start++;
    }

    return temp;
}//end reverse



//uses functions make_lower, remove_punct
bool is_pal(const string& s)
{
    string::const_iterator sForward = s.begin();
    string::const_reverse_iterator sBackward = s.rbegin();
    bool palindrome = true;

    for(; sForward < s.end(), sBackward < s.rend();)
    {
        if(!isalpha(*sForward)) {
            sForward++;
            continue;
        }
        if(!isalpha(*sBackward)) {
            sBackward++;
            continue;
        }
        if(tolower(*sForward) != tolower(*sBackward))
            palindrome = false;
        sBackward++;
        sForward++;
    }
    return palindrome;
}